ENT Flashcards
what is the role of semicircular canals in the ear? what are they filled with?
- to sense head movement
- endolymph
what is the eustachian tube? what are its 2 roles?
- tube connecting middle ear with the throat
- equalises pressure in the middle ear
- drains fluid from middle ear
role of the cochlea?
converts sound vibration into nerve signal
when is hearing loss classed as “sudden onset”?
when it occurs in less than 72 hours
what might hearing loss with associated pain / discharge indicate?
outer / middle ear infection
how is weber’s test performed?
- get tuning fork vibrating
- place in middle of pt’s forehead
- ask if they can hear the sound and which ear it is louder in
what is the result for weber’s test in sensorineural hearing loss?
sound is louder in the normal (unaffected) ear
what is the result for weber’s test in conductive hearing loss?
- sound is louder in the affected ear
- deaf ear feels the need to “turn up the volume”
how is rinne’s test performed?
- get tuning fork vibrating
- put it on the mastoid process and ask if they can hear it (bone conduction)
- when they can no longer hear it, move the tuning fork 1cm from their ear and ask again (air conduction)
- repeat for opp ear
what is a normal rinne’s test result?
- pt can hear the sound again when fork lifted off the mastoid process
- air conduction is better than bone conduction normally
what is the finding of an abnormal (negative) rinne’s test? what might this indicate
- sound NOT heard again once tuning fork moved off of bone (bone > air)
- conductive hearing loss
causes of adult onset sensorineural hearing loss?
- presbycusis
- noise exposure
- meniere’s disease
- labyrinthitis
- acoustic neuroma
- neuro conditions
- infection (e.g. meningitis)
- drugs
neurological causes of sensorineural hearing loss?
- stroke
- MS
- brain tumours
drug causes of sensorineural hearing loss?
- furosemide
- gentamicin
- chemotherapy (e.g. cisplatin)
causes of adult-onset conductive hearing loss? hint: blockage
- ear wax
- foreign body in ear canal
- infection (otitis media / externa)
- middle ear effusion
- eustachian tube dysfunction
- perforated tympanic membrane
- osteosclerosis
- cholesteatoma
- exostoses
- tumours
what are exostoses?
benign bone growths in the ear
what is presbycusis?
age-related sensorineural hearing loss
pathophysiology of presbycusis?
loss of hair cells and neurones in cochlea
risk factors for presbycusis?
- ageing
- male sex
- FHx
- loud noise exposure
- DM
- HTN
- ototoxic drugs
- smoking
presentation of presbycusis?
- gradual, insidious hearing loss
- high pitched sounds go first
- associated tinnitus
how is presbycusis diagnosed?
audiometry
management of presbycusis?
- optimise environment (reduce ambient noise)
- hearing aids
- cochlear implants (2nd line)
what is sudden sensorineural hearing loss (SSNHL)? commonest cause?
- hearing loss over less than 72 hours unexplained by other causes
- emergency!!!
- 90% cases are idiopathic
conductive causes of sudden-onset hearing loss?
- ear wax / foreign body blocking canal
- otitis media / externa
- middle ear effusion
- eustachian tube dysfunction
- perforated tympanic membrane
causes of SSNHL?
- idiopathic
- infection
- meniere’s disease
- drugs
- MS
- migraine
- stroke
- acoustic neuroma
- cogan’s syndrome
diagnostic criteria on audiometry in SSNHL?
at least 30 dL in 3 consecutive frequencies
investigations in SSNHL?
- audiometry
- MRI / CT head to rule out stroke / acoustic neuroma
management of SSNHL?
- immediate referral to ENT
- treat underlying cause (e.g. ABx for infection)
- steroids if idiopathic (PO, intra-tympanic injection)
which other conditions might eustachian tube dysfunction be related to?
- URTI
- allergies (e.g. hayfever)
- smoking
presentation of eustachian tube dysfunction?
- reduced / altered hearing
- popping / fullness sensations in ear
- pain
- discomfort
- tinnitus
when does eustachian tube dysfunction worsen? give some examples
- when external air pressure changes
- air travel
- on a mountain
- scuba diving
investigations for eustachian tube dysfunction?
- not needed if obvious
- tympanometry
- audiometry
- nasopharyngoscopy
- otoscopy (r/o otitis media)
- CT
management of eustachian tube dysfunction?
- no Tx (e.g. wait for URTI to resolve)
- valsalva manoeuvre
- decongestant nasal sprays
- antihistamines / steroid nose spray (allergies)
- otovent
- surgery
surgical options for eustachian tube dysfunction?
- adenoidectomy
- grommets
- balloon dilatation eustachian tuboplasty
what is otosclerosis? what does it result in?
- remodelling of small bones in middle ear
- conductive hearing loss
risk factors for otosclerosis?
- female sex
- age <40
- FHx
presentation of otosclerosis?
- bilateral hearing loss (low-pitched lost first)
- bilateral tinnitus
- reports own voice sounding louder, so speaks quietly
findings O/E in otosclerosis?
- normal otoscopy
- normal weber’s (if bilateral)
- negative rinne’s (bone > air)
investigation of choice (and findings) in otosclerosis?
audiometry shows hearing loss at lower frequencies
management of otosclerosis?
- hearing aids
- stapedectomy / stapedotomy
what is otitis media often preceded by?
URTI
commonest causative organism(s) of otitis media? hint: think pneumonia
- streptococcus pneumoniae (pneumococcus)
- then: H. influenzae
presentation of otitis media in adults?
- ear pain
- reduced hearing in affected ear
- fever, fatigue
- URTI symptoms
- vertigo (if vestibular involvement)
- discharge (burst membrane)
otoscopy findings in otitis media?
- bulging, red tympanic membrane
- discharge in ear canal if membrane has burst
management of otitis media?
- most resolve spontaneously over 3 days
- paracetamol / ibuprofen for pain / fever
- consider ABx (immediate or delayed)
when should you consider immediate ABx in otitis media?
- significant comorbidities
- systemically unwell
- immunocompromised
when should you consider delayed ABx in otitis media? when can these be claimed?
- 3d after prescribing
- when you suspect they’ll worsen soon
ABx of choice for otitis media? hint: remember allergies!
- 5-7d course of amoxicillin
- clarithromycin if penicillin allergic
give a common and a rare example of a complication in otitis media?
- otitis media with effusion
- mastoiditis (palpate mastoid process for this)
describe the pathophysiology of otitis externa
inflammation of the skin of the external ear canal
causes of otitis externa?
- bacterial / fungal infection
- eczema
- contact dermatitis
give 2 bacterial causes of otitis externa?
- pseudomonas aeruginosa
- staph aureus
presentation of otitis externa?
- ear pain
- discharge
- itchiness
- conductive hearing loss
signs O/E of otitis externa?
- erythema, swelling and tenderness of ear canal
- pus / discharge in ear
- neck lymphadenopathy
when might pus in the external ear canal be due to otitis media rather than otitis externa?
when the tympanic membrane has been perforated
investigations for otitis externa?
- otoscopy
- ear swab (not used often)
management of mild otitis externa?
acetic acid 2%
treatment for moderate otitis externa?
- add topical ABx + steroid
- e.g. neomycin + betamethasone + acetic acid 2% (called “otomize”)
what must you exclude before treating moderate otitis externa? hint: ABx SEs
- must check the tympanic membrane is not perforated
- because it needs macrolides which can be ototoxic
treatment of severe otitis externa?
- oral ABx
- e.g. flucloxacillin or clarithromycin
- if very severe, admission and IV ABx
management of fungal otitis externa?
clotrimazole ear drops
what is malignant otitis externa? main complication of this?
- infection which has spreads to bones outside of ear canal
- osteomyelitis of temporal bone
risk factors for malignant otitis externa? hint: immunocompromise
- DM
- immunosuppressants (e.g. chemo)
- HIV
presentation of malignant otitis externa?
- more severe version of otitis externa signs
- persistent headache
- fever
- severe pain
key finding of malignant otitis externa?
granulation tissue at junction between bone and cartilage
management of malignant otitis externa?
- admission under ENT team
- IV ABx
- CT / MRI head
presentation of impacted ear wax?
- conductive hearing loss
- discomfort / fullness in ear
- pain
- tinnitus
how is impacted ear wax diagnosed?
seen on otoscope covering tympanic membrane
management of impacted ear wax?
- most cases need nothing
- ear drops (olive oil)
- ear irrigation (water)
- microsuction
what is primary tinnitus associated with?
sensorineural hearing loss
causes of secondary tinnitus? hint: there’s a LOT
- impacted ear wax
- ear infection
- meniere’s disease
- noise exposure
- drugs
- acoustic neuroma
- MS
- trauma
- depression
drug causes of tinnitus?
- furosemide
- gentamicin
- cisplatin
systemic signs associated with tinnitus?
- anaemia
- DM
- thyroid dysfunction (hypo or hyper)
- hyperlipidaemia
what is objective tinnitus?
sound is demonstrable O/E (it is actually there)
examples of causes of objective tinnitus?
- carotid artery stenosis (causing a bruit)
- aortic stenosis
- AVM
- eustachian tube dysfunction (popping / clicking sounds)
red flag features of tinnitus?
- unilateral
- pulsatile
- associated sudden-onset hearing loss
- associated vertigo / dizziness
- headaches / visual changes
- suicidal ideation
prognosis of tinnitus?
tends to improve alone without any intervention
management of tinnitus?
- treat underlying cause (wax removal)
- hearing aids
- sound therapy
- CBT
what is vertigo?
the sensation that either the patient or their environment is moving
vestibular causes of vertigo?
- BPPV
- meniere’s disease
- vestibular neuronitis
- labyrinthitis
pathophysiology of benign paroxysmal positional vertigo (BPPV)?
- calcium carbonate crystals (otoconia) displaced into semicircular canals
- disrupts endolymph flow
course of disease in BPPV?
- onset over several weeks
- then resolves
- then recurs months later
diagnostic test for BPPV?
dix-hallpike manoeuvre
treatment of BPPV?
- epley manoeuvre
- brandt-daroff exercises
presentation of meniere’s disease?
- hearing loss
- tinnitus
- vertigo
- fullness in ear feeling
- “drop attacks” (unexplained falls)
- unidirectional nystagmus
pathophysiology of acute vestibular neuritis?
viral infection (usually URTI) causing inflammation of the vestibular nerve
what is ramsay-hunt syndrome? how does it present?
- herpes-zoster infection with associated symptoms
- facial nerve weakness
- vesicles around ear
central causes of vertigo?
anything affecting cerebellum or brainstem:
- posterior stroke
- tumour
- MS
- vestibular migraine
how does vertigo from a central cause present?
it will be sustained and non-positional
presentation of vestibular migraine?
- vertigo
- visual aura
- headaches
give an example of a trigger for BPPV
turning over in bed
presentation of meniere’s disease? hint: triad
- hearing loss
- vertigo
- tinnitus
pathophysiology of meniere’s disease?
excessive buildup of endolymph in the labyrinth of the inner ear
typical patient history in meniere’s disease?
- 40-50 year old
- unilateral episodes of vertigo, hearing loss and tinnitus
how does the vertigo in meniere’s disease present?
- episodic
- lasts 20 mins - few hours
- not triggered by movement or posture
what type of hearing loss is seen in meniere’s disease?
- unilateral
- sensorineural
- low frequencies affected first
how is meniere’s disease diagnosed?
- clinically
- followed up by audiology assessment
management of acute attacks of meniere’s disease?
- prochlorperazine
- antihistamines (e.g. cyclizine)
prophylaxis in meniere’s disease?
betahistine